Your car’s whole electrical system relies on a working alternator, so it’s important to keep it in good shape and catch problems early. Because the alternator is relevant to so many conspicuous aspects of the vehicle, signs of damage or issues can often be spotted early. Wilson Tire & Auto’s certified technicians will walk you through the sounds a failing alternator can make, as well as other symptoms to watch for.
What Does A Car Alternator Do?
Auto alternators work as generators for your car. While the battery supplies the initial power needed to start a car, alternators create the electricity needed to recharge the battery, run the electrical system, and even power electrical accessories like sunroofs or power windows.
The alternator works primarily through rotation and electromagnetics. The serpentine belt rotates the alternator’s external pulley, applying power in the form of mechanical energy. The rotor, covered in magnetic poles, moves with bearings that allow it to spin at high speeds; this combination turns the rotor and its casing — the stator — into an electromagnet producing an AC charge. The rectifier then converts the charge to DC so that it will work with the car battery and other systems. Any of these parts, as well as the internal wires, brush, or diodes can wear out over time, leading to a compromised alternator.
Sounds From a Failing Alternator
Squeaking or Squealing Sounds
If you start to notice that your car is making squeaking or squealing noises, particularly when you accelerate or turn, it may be related to the alternator, if indirectly. The serpentine belt, also called the drive belt, is not technically part of the alternator, but if the belt is damaged or not correctly fitted, then the alternator cannot work effectively. Serpentine belts can stretch, wear down, crack, or become misaligned, causing it to slip against the alternator’s pulley. This may mean the alternator is not spinning fast enough to power the battery, so the belt should be fixed quickly. Because the belt also affects the power steering pump, turning can trigger these sounds as well.
Whining or Humming Sounds
Whining sounds can be caused by worn out or damaged bearings. With use, the bearings that keep the rotor moving can get pitted, worn, or fully break. If the pitch of the humming gets higher with increased engine speed, the issue is almost certainly with the bearings. Wilson Tire & Auto techs recommend having these replaced as soon as possible. Ignoring the issue will lead to the sounds getting louder as the bearings deteriorate further, as well as an increased chance of damage to the rest of the alternator.
Grinding Sounds
If the humming was ignored, it will eventually start to change to grinding as the bearings wear down to just metal. The metal on metal can cause severe damage, and usually means the alternator will fail completely within days to weeks. If you start to hear grinding that gets more noticeable at higher RPMs, it is time to come in for repairs.
Other Signs of Alternator Damage
Sounds are not the only way of detecting a worn down or faulty alternator. Because alternators affect a car’s whole electrical system, many parts of this system will be less effective. This includes flickering or dim lights — including headlights — or weak or malfunctioning accessory features. The car’s battery may be unable to fully charge with a defective alternator, leading to a weak or no charge, meaning trouble with or an inability to start.
Some cars also have a dashboard warning light to indicate alternator issues. These can be shaped like a battery, or have the letters ‘ALT’ or ‘GEN’ for generator, as they are referred to in older cars. Warning signs can also come in the form of smells, usually burning rubber from the drive belt, or hot metal from wires and other parts overheating.
How to Prevent Alternator Damage
The best way to prevent damage to your alternator — or any part of your vehicle — is to keep up with maintenance and not overwork it. Using multiple electrical accessories at the same time can stress the alternator, especially when the car is only idling. There’s nothing wrong with taking advantage of your heated seats, phone charger, or stereo, but remember to turn them off when they aren’t needed.
Maintaining an auto alternator means maintaining the drive belt and battery as well. Battery terminals can build up corrosion, and connections can come loose, so make regular checks to ensure the electricity can move easily to and from the battery. Replacing a failing battery promptly will prevent strain, as alternators will not have to overcompensate for the weak battery.
Alternator and Electrical Repair in Nashville, TN
A faulty alternator is obviously a problem, but the sounds or other signs we mentioned above are not a reason to panic. However, they are a sign that action needs to be taken and repairs or replacements need to be made. If you are concerned that your alternator is failing, take your car to certified mechanics — like the expert auto technicians at Wilson Tire & Auto in Nashville, TN — for an accurate diagnosis of the problem. We provide a comprehensive electrical system diagnostic as part of our repair services to ensure nothing is missed.
If you are concerned about your vehicle’s alternator, need electrical repair, or just need an oil change, Wilson Tire & Auto can handle it for you. Book an appointment, stop by our shop, or give us a call.
